What is the first medication administered for unstable wide complex tachycardia?

• A. Amiodarone 150 mg IV over 10 minutes
• B. Lidocaine 50 mg IV
• C. Adenosine 6 mg IV
• D. Magnesium sulfate 2 g IV

Answer: (A)

When a patient has unstable wide-complex tachycardia, the priority is to terminate the rhythm and restore perfusion. Synchronized cardioversion is the fastest way to achieve that, but if you’re choosing a medication to administer promptly, amiodarone is the best first-line antiarrhythmic for VT. It effectively terminates ventricular tachycardia and helps prevent recurrence, with a broad range of action on ventricular tissue. The standard bolus is 150 mg given IV over about 10 minutes, with the option to repeat or start an infusion if needed.

Lidocaine is a viable alternative if amiodarone isn’t available or is contraindicated, but amiodarone generally has greater efficacy for VT and a more favorable safety profile in many scenarios. Adenosine is not effective for ventricular tachycardia and can be harmful in this context. Magnesium sulfate is specifically used for torsades de pointes or severe magnesium deficiency, not typical VT.